Specific Gravity

redsman · 09/10/2011, 07:58 PM

How do you get specific gravity to go down?

Neptune_Fan · 09/10/2011, 08:01 PM

Add Water

redsman · 09/10/2011, 08:04 PM

I have I just can't get down low enough.

Neptune_Fan · 09/10/2011, 08:05 PM

Are you adding plain water?....dont add saltwater

Bunnylicked · 09/10/2011, 08:08 PM

What's your SG at, and what are you using to measure it?

redsman · 09/10/2011, 08:08 PM

Yea just RO water.I may not be taking enough water at a time.

redsman · 09/10/2011, 08:13 PM

It's at 1.027-1.028.I'm using a hydrometer.

organism · 09/10/2011, 08:27 PM

A swing arm hydrometer? Those can be about as accurate as a taste test, your best bet if you can afford to do so is to get a refractometer and calibrate it using calibration fluid. But to answer your question ro/di water added to the tank will bring down your salinity.

redsman · 09/10/2011, 08:47 PM

How much water should I change to get it to come down?

plasmacon · 09/10/2011, 09:01 PM

You don't say if you have a 30 gallon with a 10 sump or a 150 gallon with a 75 gallon sump. If I am trying to "fix" an over site, I pull a gallon out of my sump and replace with DI water. My return section has about a 10 gallon volume. My total system volume is about 150 gallons, so I can pull out 3 gallons and not worry about it. I don't, I spread it out, I'm in no hurry.

1.028 is not a catastrophe, just take your time and bring it down to where you want it.

organism · 09/10/2011, 10:20 PM

Quote:

Originally Posted by redsman

How much water should I change to get it to come down?

It's hard to say, your salinity might be way off from whatever your hydrometer says...

Mike31154 · 09/10/2011, 10:25 PM

plasmacon is on the money here, have a look at your livestock and if it appears to be doing ok, take your time & bring it down slowly by taking a gallon or so out & adding fresh, depending on system volume of course. A salinity check with a second hydrometer or refractometer may not be a bad idea. I'm not a great fan of swing arm hydrometers, but refractometers are also prone to errors and require calibration. Until I broke my floating hydrometer I used to cross check readings with all 3 types. Actually found I liked the floating type of hydrometer the best, you just need to ensure you compensate for temperature. Other than that they're pretty bullet proof and never need calibration.

09/10/2011, 07:58 PM	#1
redsman Registered Member Join Date: Aug 2011 Posts: 148	Specific Gravity How do you get specific gravity to go down?

09/10/2011, 08:08 PM	#5
Bunnylicked Registered Member Join Date: Jul 2011 Location: Boulder, Colorado, USA Posts: 117	What's your SG at, and what are you using to measure it? __________________ -Mame "Give a man a fish, and you feed him for a day. Give a man a reef aquarium, and he'll starve from staring at it for too long." Current Tank Info: 3g JBJ pico, started August 24th, 2011

09/10/2011, 09:01 PM	#10
plasmacon Registered Member Join Date: Apr 2008 Location: Western Kentucky Posts: 110	You don't say if you have a 30 gallon with a 10 sump or a 150 gallon with a 75 gallon sump. If I am trying to "fix" an over site, I pull a gallon out of my sump and replace with DI water. My return section has about a 10 gallon volume. My total system volume is about 150 gallons, so I can pull out 3 gallons and not worry about it. I don't, I spread it out, I'm in no hurry. 1.028 is not a catastrophe, just take your time and bring it down to where you want it. __________________ Thanks Patrick Current Tank Info: 135 gallon Reef

09/10/2011, 10:25 PM	#12
Mike31154 Registered Member Join Date: Apr 2008 Location: B.C. Canada Posts: 1,555	plasmacon is on the money here, have a look at your livestock and if it appears to be doing ok, take your time & bring it down slowly by taking a gallon or so out & adding fresh, depending on system volume of course. A salinity check with a second hydrometer or refractometer may not be a bad idea. I'm not a great fan of swing arm hydrometers, but refractometers are also prone to errors and require calibration. Until I broke my floating hydrometer I used to cross check readings with all 3 types. Actually found I liked the floating type of hydrometer the best, you just need to ensure you compensate for temperature. Other than that they're pretty bullet proof and never need calibration. __________________ Mike Current Tank Info: 77g sumpless sw with rock, sand, a few critters, fishes & polyps. Lights, pumps.....

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09/10/2011, 08:01 PM	#2
Neptune_Fan Registered Member Join Date: Oct 2010 Location: Port St Lucie, FL Posts: 224	Add Water

09/10/2011, 08:04 PM	#3
redsman Registered Member Join Date: Aug 2011 Posts: 148	I have I just can't get down low enough.

09/10/2011, 08:05 PM	#4
Neptune_Fan Registered Member Join Date: Oct 2010 Location: Port St Lucie, FL Posts: 224	Are you adding plain water?....dont add saltwater

09/10/2011, 08:13 PM	#7
redsman Registered Member Join Date: Aug 2011 Posts: 148	It's at 1.027-1.028.I'm using a hydrometer.

09/10/2011, 08:27 PM	#8
organism code monkey Join Date: Dec 2004 Location: south bay Posts: 6,223	A swing arm hydrometer? Those can be about as accurate as a taste test, your best bet if you can afford to do so is to get a refractometer and calibrate it using calibration fluid. But to answer your question ro/di water added to the tank will bring down your salinity.

09/10/2011, 08:47 PM	#9
redsman Registered Member Join Date: Aug 2011 Posts: 148	How much water should I change to get it to come down?